I also think that part of it is that after having been forced and forced in the male mold for so long, and not feeling like it's you, then at some point you begin to think it's not just not you, but that it's evil, bad all short. It's easy to go from "it's not for me" to "it's bad". Just like food. It's easy to say it's bad instead of "I don't like it".
That, and there might be resentment against guys who, in the past, made fun of you for not being a "real" guy, or for forcing you to become more like one.
Me, uhm... I feel more understood by women, and I feel like I belong more with them. It's not like I dislike guys... more that until now they've secretly disliked me for not being a real guy, so I didn't really get much of a chance to socialize with them at all. Not to say that I socialize with women much more, since I'm quite alone in every way, but anyway, girls really do tend to have less automatic disdain for "fake" guys.
Even though I did have a period when I thought all about masculinity was evil, because of how much I've always hated everything masculine about me and found it weird in others, I'm getting out of it. I still understand very little if anything about all that is masculine, but I try to understand that I can dislike it without it being a bad thing.